Ground anchor



May 14, 1968 w. E. wAlrE GROUND ANCHOR Filed sept. 2e, 196e WILL/AM. E.WAI/TE.

United States Patent O 3,382,628 GROUND ANCHOR William Edmund Waite,Thnrland, Crookshury Road, Rnnfold, Surrey, England Filed Sept. 26,1966, Ser. No. 581,300 Claims priority, application Great Britain, Sept.28, 1965,

,273/65 2 Claims. (Cl. 52--157) ABSTRACT F THE DISCLOSURE An adjustableground anchor is disclosed in which the shaft length can be changed byrotation of one part of the shaft with respect to another where they arejoined at a threaded connection. The smaller shaft part extends theentire length through a hollow portion of the shaft and is preventedfrom being pulled out therefrom by a stop means on the remote anchorblade end thereof.

This invention relates to ground anchors, as used for example for theanchoring of cables serving to hold fence poles, telegraph poles and thelike in position.

A well known construction of ground anchor incorporates a shaft having ahelical anchor blade. The device is driven into the g-round by engaginga suitable tool 0r rotary drive with the shaft and rotating the anchorto cause the -blade to screw itself into the ground to an adequatedepth. A cable connection is then made to the protruding end of theshaft.

It is desirable, with such ground anchors, to provide for some degree ofadjustment of the assembly of cable and anchor, e. g. to take up slackwhich may occur in the course of time. One common means used hithertohas consisted of a turnbuckle incorporated along the length of thecable, or between the cable and the shaft of the anchor.

The provision of two separate items, i.e. the anchor and the turnbuckle,has disadvantages in that a number of separate connections must be madebetween the anchor, the turnbuckle, and the cabfe, and two separateitems must be stored, transported and handled. It is accordingly theobject of the present invention to provide an improved construction ofground anchor which incorporates an integral means for adjustment of itslength, whereby -adjustment of cable tension can be carried out byadjustment of the anchor itself, and the need for a separate turnbuckleis eliminated.

According to the present invention, a ground anchor comprises a shaftwith two portions engaged one to the other by threading, an anchor bladeon one such shaft portion, and means for connecting a cable on the othershaft portion, the axial separation of the anchor blade and the ca'bleconnecting means `being adjustable by rotation of one shaft portion withrespect to the other.

With such an arrangement, adjustment of the cable tension may beobtained merely -by rotation of that portion of the shaft whichprotrudes from the ground, with respect to the other portion having itsblade buried in the ground.

To enable the respective portions to be rotated readily, the cableconnecting means preferably includes a cable attachment element which isfreely rotatable with respect to the shaft portion on which it isprovided. Such an element may be, for example, in the form of a swiveleye.

One portion of the shaft may conveniently be a tube carrying an anchorblade, the other portion being a stem threaded coaxially into the tube,a protruding end of said stem carrying the cable connecting means.

In order to reduce the amount of internal threading to a minimum, it isconvenient to make the tube shorter 3,382,628 Patented May 14, 1968 thanthe stem and internally threaded for only part of its length, thenecessary full length of adjustment being obtained by forming a malethread along a somewhat longer length of the stem. In such aconstruction, to protect the exposed threading of the stem, the tube maycarry at one end a tubular extension arranged coaxially and withclearance about the stem, and which accordingly protects the threadagainst physical damage and corrosion.

Because the normal place of use of such ground anchors is in the groundand out of doors, there is considera'ble liability to corrode. For thisreason, it is desirable to galvanise the device at the exposed portions.On the other hand it is not convenient or desirable for ease ofmanufacture, to galvanise the threaded portions. Accordingly, thetubular extension covering the male threading of the stem may lalsoserve, during plating, as a means of masking off the threading from thegalvanising bath. For this purpose, any convenient temporary seal may beintroduced at the mouth of the extension to seal the gap between it andthe threaded stem.

In a preferred arrangement, the other end of the stern, remote from thecable connection, carries a protruding head of greater diameter than thebore of the tube, said head being preferably pointed to facilitate entryof the anchor into the ground.

Such a head may 'be of generally conical cross-section and preferablyhas its base of the same diameter as the exterior of the tube. The headmay also serve as an end stop to prevent the threaded stem from beingcompletely disengaged from the tubular portion.

The shaft portion carrying the anchor blade may be provided with amulti-faceted exterior for engagement with a correspondingly faceted keyof a power drive means.

The shaft portion carrying the cable connecting means may be providedwith any suitable formation to facilitate its engagement with a tool forrotation with respect to the other shaft portion, e.g. a faceted nutwelded onto it. Said nut may also serve as a stop for the adjustment ofthe stem in the `downward direction.

In order that the nature of the invention may be readily ascertained, anembodiment of ground anchor in accordance therewith is hereinatferparticularly described with reference to the accompanying drawing inwhich the single iigure is a side elevation with parts shown in section.

In the anchor illustrated, there is provided a two-part shaft includinga short heavy-gauge outer tube 1 having an internal threading 2 forabout one-fifth of the length of its bore from the top end downwards.Externally the tube is of square or other multi-faceted cross-section.At an approximately central position along the tube there is Welded ahelical blade 3. Coaxially onto the upper end of the tube 1 there iswelded a somewhat shorter length of relatively light-gauge conduit 4which has an internal diameter greater than that of the threading andwhich is intended to act as a shield. Within the tube 1 and conduit 4there is disposed a -stem 5 consisting of a piece of solid rod ofcircular cross-section and threaded externally at 6 for about thecentral third of its length, The threading 6 is engaged in the threadingZ of the tube 1. The lower end of the rod 5 has a coaxial conical head 7welded onto it, and the greatest diameter of the head is larger than thediameter of the bore of the tube 1.

The conduit 4 lits with clearance about the stem, and in practice itwould be convenient `to provide a packing adjacent the open upper end ofthe conduit to provide a seal against dirt and moisture. Such a packingmay also serve to prevent deposition of plating metal on the thread 6,when the stem is appropriately threaded into the tube 1.

The upper end of the stem 5 has an enlarged head 8 which serves toretain a freely rotatable swivel eye 9 for attachment of the usualcable.

Below the eye 9 there is welded a square-section nut 10 to serve forengage-ment by a Spanner (not shown) for rotating the stem.

When the anchor is to be driven into the ground, the threaded stern 5 isretracted upwardly until the conical head 7 is butted up against thelower end of the tube 1, thereby sealing the lower end of the tubeagainst the entry of soil. The anchor is then rotated by means of apower-operated device having a tubular key with internal facets whichrnate with the faceted exterior of the tube 1. This rotation causes theblade 1 to be driven down into the ground.

After the usual cable has been attached to the swivel eye 9, the tensionof the cable can be adjusted by r0- tation of the stern 5, using aspanner engaged with the nut 10. The stern can be adjusted axiallythrough the tube 1 for the whole of the length of threading of the stem,say about twelve inches in an anchor of length approximately three feet.

I claim:

1. A ground anchor comprising a shaft having a tubular portion carryinga radially projecting rigid anchor blade, a stern portion threadedcoaxially into said tubular portion, said tubular portion and sternportion being rotatable one with respect to the other for lengtheningand shortening the shaft according to the direction of relative rotationimparted to said shaft portions, said stem portion having a first endprotruding from said tubular portion and carrying a rotatable cableconnector means, said stern portion having a second end protruding fromsaid tubular portion and carrying a head of greater diameter than thebore of the tubular portion.

2. A ground anchor comprising a shaft having a tubular portion carryinga radially projecting rigid anchor blade, a stern portion threadedcoaXially into said tubular portion, said tubular portion and stemportion being rotatable one with respect to the other for lengtheningand shortening the shaft according to the direction of relative rotationimparted to said shaft portions, said stem portion having a first endprotruding from said tubular portion and carrying a rotatable cableconnector means, and stop means on the stern portion and on the tubularportion positioned to abut to prevent the stem portion from beingentirely removed from the tubular portion.

References Cited FRANK L. ABBOTT,

G. W. HORNADAY, R. S. VERMUT, P. C. FAW,

Assistant Examiners.

Primary Examiner.

